Controller setup trouble...help please. (Black Ops
2)

Ok so I've never had trouble playing MP or anything else in the game. But when I started playing it maybe 2 hours after I played it my right side of the joystick is doing the opposite of what it was normally always been doing. When I want to look up I look down instead vice versa. What was weird, I checked the controls for all the controller set up in the options. And there is NO option for what it normally should be on..So I'm stuck now. Please someone help. Thanks in advance.